Scientists say they have developed a cocktail of seven fruit juices that boosts health, cuts the risk of heart disease and stroke – and tastes good. The ‘super-smoothie’ contains grapes, apples, blueberries and strawberries.

Heart healthy: French scientists have created a fruit cocktail with an ideal blend of 13 different juices that could help lower the risk of coronary disease

However, there are exotic additions. These include the so-called superfoods cowberry (aka lingonberry) – a tart, red fruit related to the cranberry – and acerola, a red cherry-like fruit that has 30 times more vitamin C than orange juice.

The final ingredient of the smoothie is aronia, or chokeberry, an American blackberry once described as the ‘healthiest berry in the world’.

Past studies have shown that compounds in fruit called polyphenols protect the heart and help prevent clogged arteries.

French scientists say their smoothie contains the healthiest and best tasting combination of fruit juices.

Blends of 13 different purees and juices were analysed in a laboratory for their effects on pig arteries.

But the finished recipe was selected after tests by 80 volunteers.

In tests, heart artery walls relaxed when they were exposed to the fruit juice cocktail. The researchers, from the University of Strasbourg, say that in a human, this would boost the flow of blood to the heart and ensure it got a healthy balance of nutrients and oxygen.

The team – who report their findings in the Royal Society of Chemistry journal Food and Function – also measured the antioxidant ability of different recipes to neutralise harmful molecules in the body that can damage DNA and cells.

The study found that some polyphenols were more potent than others – and that their ability to mop up harmful ‘free radicals’ that can damage DNA and cells was more important than the amount of polyphenols in each fruit.

Tracy Parker, of the British Heart Foundation, said: ‘This research adds more weight to evidence that eating fruit and vegetables is good for us in terms of reducing our risk for heart disease.

‘However, we still don’t fully understand why, or whether certain fruits and vegetables are better than others. Even this study acknowledges that scientists can’t yet explain any link.

‘What we do know is that we should all eat a wide range of fruit and veg as part of a balanced diet, and fruit juice is a tasty and handy way of doing this.

‘Don’t forget though, juice contains less fibre and more sugar than the original fruit so it only counts as one of our five-a-day.’